RESUMO
This work describes the synthesis of three destruxin E cyclodepsipeptidic analogs. These compounds have an identical amino acid sequence but differ by the nature of the hydroxy acid residue with is 2-hydroxy-3-phenylpropionic (Hpp), 2-hydroxy-5-trimethylsilyl-4-pentynoic (Hpy-TMS) and 2-hydroxy-4-pentynoic (Hpy) acid, respectively. The insecticidal properties on the Galleria mellonella larvae (paralysis and lethal effect) of these analogs are presented in comparison with the natural destruxin E. All these compounds have toxic effects, the most potent being Hpy that induces the same effect as destruxin E.
Assuntos
Depsipeptídeos , Proteínas Fúngicas , Inseticidas/química , Inseticidas/síntese química , Peptídeos Cíclicos/química , Animais , Fungos/química , Inseticidas/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Mariposas , Peptídeos/síntese química , Peptídeos/química , Peptídeos/toxicidade , Peptídeos Cíclicos/farmacologia , EstereoisomerismoRESUMO
A general strategy for the synthesis of destruxin analogues is described and applied to a particular example, D-Lac-6 destruxin E. The tetrapeptide Boc-Ile-N-MeVal-N-MeAla-beta-Ala-OMe (2) was chosen as the basic starting compound, and its preparation was optimized. This fragment was then coupled with the compound (D)Lac-Pro, and the resulting peptide was cyclized by the DEPC or DPPA/HOBt/DMAP methods at 21 and 30% yield, respectively. The biological activity of the analogue obtained was established by injection to an insect host.
